From 202cd2a6d52369788080fa4345b21903233aa5a7 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Tue, 6 Jul 2021 11:13:35 +0200 Subject: [PATCH] ipv6: fix 'disable_policy' for fwd packets The goal of commit b17168d7e2cc ("ipv6: Provide ipv6 version of "disable_policy" sysctl") was to have the disable_policy from ipv4 available on ipv6. However, it's not exactly the same mechanism. On IPv4, all packets coming from an interface, which has disable_policy set, bypass the policy check. For ipv6, this is done only for local packets, ie for packets destinated to an address configured on the incoming interface. Let's align ipv6 with ipv4 so that the 'disable_policy' sysctl has the same effect for both protocols. My first approach was to create a new kind of route cache entries, to be able to set DST_NOPOLICY without modifying routes. This would have added a lot of code. Because the local delivery path is already handled, I choose to focus on the forwarding path to minimize code churn. Fixes: b17168d7e2cc ("ipv6: Provide ipv6 version of "disable_policy" sysctl") Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller --- net/ipv6/ip6_output.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 984050f35c61f..d4ee2169afd81 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -479,7 +479,9 @@ int ip6_forward(struct sk_buff *skb) if (skb_warn_if_lro(skb)) goto drop; - if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { + if (!net->ipv6.devconf_all->disable_policy && + !idev->cnf.disable_policy && + !xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); goto drop; } -- 2.39.5